Vacuum-operated gear shifting device



April 26, 1938. H. N. DURHAM r 2,115,097

VACUUM OPERATED GEAR SHIFTING DEVICE Filed April 6, 1934 %1I4%\ITOR 31M NEW...

ATT RN EYS Patented Apr. 26, 19 38 FATE VACUUM-OPERATED GEAR smr'rma nsvrca- Hobart N. Dnrham'Manhasset, N. m, assignor by mesne assignments, to Vaco Products, I"): v a corporation of. Delaware t Application April a, 1934, Serial No. 719,211-

,8 Claims. (01. 192-41) s The present invention relates to 'vacuuJn-oper ated gear shifting means for automotive'vehioles, I and more particularly to a noveland-improved' gear shifting means for automatically selecting the gear ratioin accordance .with the speed of the vehicle. V

Objects and advantages of the invention will be setforth inpart hereinafter andin part will be obvious herefrom, or may be learned by practice with the invention, the same being realizedand attained by means of the instrumentalities and. combinations pointed out in the appended claims. r

The invention consists'in the novel parts, construct'ion, arrangements, combinations and improvements herein shown and described.

The accompanying drawing, referred to herein and constituting a part hereof, illustrates one embodimentof the invention, and together with the description, serve to explain the. principles of the invention.

The single figure of the drawing is a diagrammatic view showing an illustrative embodiment of the present invention. v

The present invention has for its object the provision of a novel and. improvedspeed controlled, vacuum-operated gear shifting device particularly adapted for'use with automotive ve hicles. Another object, is the provision of a vacuum-operatedseflr shifting device in which the gears cannot be shifted to a reverse speed while the vehicle is moved forwardly, and' vice versa. Still another object is the provision of a vacuum-operated gear shifting f device having. means preventing the engagement of the clutch while the gears are being changed from one speed to another, or when they are not in meshed or power-transmitting relation. r

In accordance with the illustrative embodiment ofthe invention, an internal combustion engine transmits power through ai ciutch and conventional change speed gearing to themepeller shaft of a vehicle Means are. providedfor releasing the. clutch by the suction created by the engine, these means being operative to release the clutch whenever the throttle is closed, and operative to cause engagement of the clutch under certain conditionswhenever the throttle is open. Means are also provided for preventing shifting from one speed to another unless the clutch is released, as well as for preventing engagement of the clutch except when the gears are fully meshed in one position or another, thereby preventing any clashing of the gear piece while shifting.

when the clutch is disengaged, vacuum operated means controlledby the speed of the vehicle' operate to shift the gears "into the proper speed as determined by the vehicle speed. Other means are provided influencing the. shifting control 5 i mechanism so 'thattoo frequent or unnecessary shifting of gears is avoided, also serving to elim inate anyneutral points on'controlwhich might otherwise exist. Means under control ofthe op-' erator are also provided for shifting jthegears'io into reverse speed when so desired.

It will "be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory NT fum s} of the inventionybut are not restrictive thereof. l5

Referring now in detail to the illustrative embodiment oi the invention as'shownin the accompanying drawing, there is provided an in ternal combustion engine l0 adapted to drive:

propeller shaft I], through clutch-i2 and a selective, change speed transmission. I 3 of conventional construction. "The engine I0 is provided with the usual intake manifold il "in which is positionedta throttle valve II to regulate the Clutch l2 is adapted to be opened and closed by movement of the clutch pedal l1, and is normally held in engaged or power-transmitting relation by the premureof spring l8, compressed between the clutch release collar l9 and the stationary 30 gfiow' of combustible mixture. to the engine. f

tor peda1'2l, and for this purpose, piston 21 is, v

connected with the clutch pedal l1 by"iink2l and is slidable in cylinder :9. Clutch 1: isfre-j. 40

leasedpy means of suction applied to the cylinder 28 throughsuction pipes 30 andit whichv connect cylinder "with the engine side oftheli intake manifold II, and the operation of cylin der 2! is controlled by the. accelerator pedal 2| through valve 33. 'This, valve comprises avalve plunger 34 positioned-within a cylinder 35 the plunger being connected with the accelerator pedal through link'fl. Plunger 34 is cut awayso that in the closed position of the throttle and, g when the engine is idle, suction is applied by connecting pipes II and 3], whereason opening i the throttle, pipe ii is blocked and pipe l ifis connected to atmosphere through pipe 38 serv-' ing to bleed the cylinder 2! and allow engagel6 50 speed pipcfll'is connectedto theforward end of 2 J V o ment'of the clutch I! under the influence of no s ll. v 1

The transmission l! is of theconventional selective sliding gear type and may comprise :gears for-driving the car in reverse, first,- second a and As is usual, such gearlng is adapted to be'shifted from one speed to another by means of two-independently operable, slidable forksand "ll,either of which may be moved from neutral to either or its other positions while the other fork'is in its central and neutral posttion. Movementofthe rel-1: u to. the right shifts 1 the gears into reverse, movement to the extreme left position shifts them toiirst speed, and by s returning the fork II to its central position; the

m1: ll may be-shifted tothe -right to shift the gearstosecondspeedortothelefttoshiftthem 'intodirectorhighspeed.

Means are provided lmder control of the clutch for preventing movement of the gear shifting forks ll and II except when the clutch is disengaged. Ail-embodied, each of'the'forks ll and ll is rigidly connected to'a slidable piston'rod l2 and 3;. andjthese rodsfat oneend are, pros.

vided with. notches" .44 adapted to be engaged by pivoted latches ll thereby holding the rods against movement. l! are pivoted at ll and connectedtogether'at their forward end the pivotcd'bell crank it. A spring It is p by link 41; adapted tofbe moved by plunger It operating through pinandslot connections in vided for :forcingthe plunger, ll against the clutch lever H to cause engagement of the latches agaimt shifting; movement.-

ll withone notch ll on each rod whenever the clutch is engaged, thereby locking the, gears vacuum operated ,means- ,are provided. for

- shifting, the geare'by movement, of the forks. i 'and' lLand as erabodied, twopistons l2 and I are provided, operatingjinlcylinders l4- and II respectively. For moving :the pistons l2 and within their respective cylinderslvacuurn "pipes; connected with theintake manifold oftheengine, are provided. Neutralpipesll and Ii are connected to the centralportion of cylinders N and II respectively, while thereverse pipe '82 is con nected-toithe rearendof cylinder tame-mg speed pipe It is connected to the forward endef this cylinder, the second; speed pipe it is con-' nected to the rear endof cylinder I and the high cylinder 5}. By applyingyacuumto the cylinders 'through these pipes, the, pistons)". and It I and the gear shifting'iorks ll andil'fithe gears,

may be shifted to their several positionsJ'T ,7

Speed controlled means" operating in accord,- anoe with the vehiclespeed are operated for con,-

I trolling the connectionof the various pipes to the "intake manifold, and fort-his purpose" a cenjjtri'fu'gal governor II is driven from the propeller shaft II and is provided witha grooved'collar Ii cooperatingwith a pin 'llprol ifli l' laterally;

' 'irom' a valve plunger 13 slidable in valve casing 70 v time the air is exhausted through pipes ll and to positionthepistons l2 and II in first f 1. In'the position shown in the drawing, which.

. 65, t v V 'rest ,orfslowly moving,"the pipes'll and I areis thefposition of the parts withfth'evehicle at connectedjthrough the valve to the-pipe I! through the clutch-operated valve II to pipe 'II which opens into the intake manifold. Valve .10 is open only'when theclutch is disengaged, andat I speed position, 'as'sho'wn; As the speed of the vehicle increases (for instance to 8 M. P. 11.), the valveplunger II is moved downwardly, clos-' ingoflthepipes Cl and 08 II and N to the intake'maniiold as soon as the operator next closes the-throttle to cause disengagement-of the clutch i2 and opening of the e I2 is preferably considerably en the automobile is at rest andithe 'op-' eratorsfoot is'oi! the. accelerator pedal iifthe. parts are in the position shown in the drawing.

valve It. Under these conditions, the piston II is returned to its central or neutral position,- and' piston 53 is moved to its second speed position.

and connecting pipes '7 The operator may then again open the throttle causing enllsement of the ,clutch' and acceleration of the vehicle, and when ,sufilcient speed (say 15 M. P. H.) has been. attained to move the valve it to itshighspeed position, pipes 60 and tare connected with the intake manifold so" 7 that when the clutch is next disengaged,'the pis- I tcri II is moved vto ltshigh speed position...

. I 'orpreventing the valve plunger It fromv remaining'in inoperative or dead positions, when shifting should 1 take place," means are provided for retarding and then assisting-movement of the plunger from one to another of its positions. As.

embodied,the end of the plunger II is toothed as at ll the indentations between the teeth cor-' responding tdthe proper geabshifting positions y of the valve, and a spring;pressed detent til flts within theindentation andis adapted to, bedisplaced on movementof the valve plunger It. Pin

smaller than the] Y groove in collar 1| so as toprovide lost motion; 7

permitting'thevalve plunger to jump from one positionito the next. v I v I Forshifting the gears'to reversespeedposition. a reversing'valve is'provided' adapted for manual operation. This valve is positioned in the line It and comprises a stationary shell 8| withinwhich is rotatable a valve core 82 connected to the operating lever. In its forward'position the valve core 82 connects the line ll with the valve body ll, whereas by rotating thecore 82 counterclockwise the pipe II is connectedto pipe 6 2, 'c'aus mg" piston 52' be moved shifting the gears into reverse; A manual control lever 05, conveniently positioned, is connected to lever t3 by means vof rod is.

, Means are provided for preventing movement of valve core 82 while the vehicle-is in motion, and

for this purpose lever "is notched as'atl'l and whenever the vehicleis stationary.

pistons from one position to another.

'fMeans are also provided for preventing engagementof the clutch except when the gears are:

iully meshed in one'speed or another. say-em bodied, each of the rods 42' and 48 isprovided with a cam" 92 cooperating with valves 93 which are adapted to admit air to'pipe It; When pistons 52 and" are'in neutral positio'n,both. valves 03 are closed, andair is notadmitted'to cylinder 28 to engage the clutch except when one'orth'e' other of pistons 52 and "has been m'oved'to a gear meshing position, thereby opening one or the other oi'the valves 83. r

The operation of theillustrati've embodiment drawing may be summarized as folif shown in the Asthe throttle is opened, the clutch-operating! cylinder Il'isbled through valve 'tfa'ndthe transn'iission-controlled valve 93, thereby causing the clutch to engage, locking the gear-shii'tbeen reached, the governor III has moved the slide valve 13 to its second speed position, and when the operator next releases his foot from the accelerator pedal 2|, vacuum is applied through valve 34 to disengage the clutch l2, thereby opening the valve 16 and applying vacuum through valve 82 and valve 13 to pipes ill and 64, centering piston 52 and moving piston 53 to second speed position. While the clutch i2 is released, the latches 45 are also released, permitting movement of the pistons 52 and I3. Valves 83 are open-to permit engagement of the clutch only when one or the other of the pistons 52 and 53 has been moved from central or neutral position. When the operator next depresses the accelerator pedal 2|, the car accelerates and with, the throttle sufilciently open, reaches a speed such that valve slide 13 is moved to high speed position. When the operator releases the accelerator pedal, the operations previously described follow and vacuum is applied through pipe 65 to shiit pistons 53 to high speed position. The operator may then open the throttle-again, causing the clutch to be engaged and locking the transmission gears in high speed position.

Whenever the automobile is in motion, either forward or reverse, the governor 10 moves the latch 88 into engagement with one or the other of notches 81, preventing any movement of the reversing valve 82. While the car is stationary, the valve 82 may be moved to. reverse position,

and when so moved, vacuum line I! is connected to the vacuum line 82. With the clutch disengaged, suction is applied to line 62, moving the piston 52 to the right or into reverse position. Thereafter, on opening the throttle, the clutch is engaged locking the piston rods 42 and 43 against movement.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is:

1. A gear shitting device for automotive vehicles having a vacuum producing source of power, a clutch, change speed gearing through which the vehicle is driven including in combination vacuum operated means for changing gears, vacuum operated means for disengaging said clutch, speed controlled means for controlling said first means, a fuel control element for controlling operation of the clutch disengaging means and means preventing engagement of said clutch while the" gears are being changed from one speed to another.

2. A gear shifting device for automotive vehicles having a vacuum producing source or power, a clutch, change speed gearing through hicles having an 'sition when the vehicle is tial speed.

which the vehicle is driven including incombination vacuum operated means for changing gears, vacuum operated means for disengaging said clutch, speed controlled means for controlling said first means, a fuel control element for controlling operation of the clutch disengaging means and means preventing engagement of said clutch until after the gears have meshed.

3. A gear shifting device iorautomotive vehicles having an internal combustion engine,

change speed gearing for transmitting power drive-the vehicle and includ i y from said engine to ing in combination vacuum operated means for j shifting said gearing including a manually-operable reversing valve and means for preventing movement of said valve when the vehicle is moving.

4. A gear shifting device for automotive veinternal combustion engine, change speed gearing for transmitting power from said engine to drive the vehicle and including in combination vacuum shifting said gearing including pistons for shirting said gearing to different forward speeds and reverse. a speed controlled valve for controlling movement of said pistons. areversing valve and operated means for means preventing movement of said reversing valve when the vehicle is moving a 5. A gear shifting device for automotive vehicles having an internal combustion enginedriving the vehicle through a change speed transmission and a clutch and including in combination an accelerator controlled automotive clutch, operating means for shifting the gears of the transmission'and means preventing engagement oi" said clutch while said gears 61A gear shifting 'device are being shifted.

for automotive veacles having an internal combustion engine driving the vehicle through a change speed transmission and a clutch and including in combination an accelerator controlled automatic clutch operating means, means for shifting the gears of the transmission, means preventing engagement of said clutch while said while said clutch is engaged.

I. A gear shifting device for automotive vehicles having an internal combustion engine driving the vehicle through a change speed transmission and a clutch and including in combination vacuum operated means for disengaging and engaging said clutch under control of an-accelerator, and means controlled by the position 01' the gears for preventing engagement of the clutch under control of said accelerator. v

8. A gear shifting device for automotive vehicles having an internal combustion engine, change speed gearing for transmitting power from said engine to drive the vehicle and including in combination vacuum operated means for shifting said gearing including valve means for movement of the valve means to. its reverse pomoving at a substannoasa'r n. mmrmr.

gears are being shiftedand means preventing shitting oi said gears optionally selective reverse and means preventing 

